Cognitive and Neuropsychiatric Manifestations of COVID-19 and Effects on Elderly Individuals With Dementia

Abstract

The coronavirus disease 2019 (COVID-19) caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread worldwide and has had unprecedented effects in healthcare systems, economies and society. COVID-19 clinical presentation primarily affects the respiratory system causing bilateral pneumonia, but it is increasingly being recognized as a systemic disease, with neurologic manifestations reported in patients with mild symptoms but, most frequently, in those in a severe condition. Elderly individuals are at high risk of developing severe forms of COVID-19 due to factors associated with aging and a higher prevalence of medical comorbidities and, therefore, they are more vulnerable to possible lasting neuropsychiatric and cognitive impairments. Several reports have described insomnia, depressed mood, anxiety, post-traumatic stress disorder and cognitive impairment in a proportion of patients after discharge from the hospital. The potential mechanisms underlying these symptoms are not fully understood but are probably multifactorial, involving direct neurotrophic effect of SARS-CoV-2, consequences of long intensive care unit stays, the use of mechanical ventilation and sedative drugs, brain hypoxia, systemic inflammation, secondary effects of medications used to treat COVID-19 and dysfunction of peripheral organs. Chronic diseases such as dementia are a particular concern not only because they are associated with higher rates of hospitalization and mortality but also because COVID-19 further exacerbates the vulnerability of those with cognitive impairment. In patients with dementia, COVID-19 frequently has an atypical presentation with mental status changes complicating the early identification of cases. COVID-19 has had a dramatical impact in long-term care facilities, where rates of infection and mortality have been very high. Community measures implemented to slow the spread of the virus have forced to social distancing and cancelation of cognitive stimulation programs, which may have contributed to generate loneliness, behavioral symptoms and worsening of cognition in patients with dementia. COVID-19 has impacted the functioning of Memory Clinics, research programs and clinical trials in the Alzheimer's field, triggering the

Long-Lasting Cognitive Abnormalities after COVID-19

“…COVID-19 was initially considered almost exclusively a respiratory syndrome, but increasing evidence indicates that SARS-CoV-2 infection also affects other body districts and functions [ 1 ]. More specifically, studies have shown that SARS-CoV-2 is capable of invading the central nervous system (CNS) and causing neurological symptoms [ 2 , 3 , 4 , 5 , 6 ]. Indeed, many coronaviruses are capable of altering the structure and function of the nervous system [ 7 , 8 ].…”

Divulging the Intricacies of Crosstalk Between NF-Kb and Nrf2-Keap1 Pathway in Neurological Complications of COVID-19

“…Binding to ACE2 receptors also leads to increased blood pressure that increases the chances of cerebral hemorrhage [ 7 ]. Mechanisms involved in cognitive decline are not yet fully clear but can be attributed to direct infection of the nervous system, the systemic hyper inflammatory response, acute respiratory distress syndrome (ARDS), invasive ventilation, and sedation or side effects of the drugs used for COVID-19 [ 52 ]. Figure 4 depicts the various possible routes of neuro-invasion of SARS-CoV-2.…”

“…As discussed earlier in the article, few studies have reported short-term memory loss and neurocognitive disorder following COVID-19 infection. Majorly proposed mechanism of neurodegeneration is chronic systemic inflammation [ 52 ]. A study established the correlation of inflammatory factors and levels of C-reactive protein (CRP) in the patients that exhibited cognitive dysfunction.…”

Folgen der COVID-19-Pandemie für Menschen mit Schizophrenie, Demenz und Abhängigkeitserkrankungen

“…Eine Analyse von über 40.000 COVID-19-Patienten zeigte neuropsychiatrische Manifestationen bei 22,5 % der COVID-19-Patienten [ 28 ]. Zu nennen sind vor allem Insomnien, Depressionen, Kopfschmerzen und Enzephalopathien [ 28 , 29 ]. Die potenziell irreversiblen kognitiven Defizite bei älteren Patienten nach durchgemachter COVID-19-Erkrankung sind annehmbar multifaktorieller Genese [ 29 ].…”